Rates of comorbid affective disorders in alcohol-dependent individuals are significant. Biomarkers of alcohol use may support the diagnosis of high and frequent alcohol use in these individuals. The aim of these analyses of the WHO-ISBRA Study on State and Trait Markers of Alcohol Use and Dependence is to compare biomarkers of alcohol use across individuals with and without comorbid alcohol dependence and affective disorders. Significantly, higher values of these biomarkers are hypothesized in individuals with comorbid disorders compared to alcohol dependence only. Assessment of Alcohol dependence and comorbid depression and bipolar disorders were conducted using an adapted version of the Alcohol Use Disorder and Associated Disabilities Interview Schedule (AUDADIS). Altogether, n = 1863 individuals were included into the analyses, of whom n = 299 had a lifetime history of depression and n = 20 a bipolar disorder. Clinical characteristics like mean alcohol intake last month and biomarkers including ASAT, GGT, CDT, 5-HTOL/5-HIAA ratio and MAO-Activity were included into the analyses. Results indicate that AD only subjects had higher measures of all biomarkers compared to comorbid bipolar and depression subjects, while the latter had a higher alcohol intake during last month.

Since this is a cross-sectional study, conducted in emergency rooms of several countries, this allegedly divergent result in alcohol intake in comorbid subjects compared to higher biomarkers in AD only subjects may indicate that drinking is more frequent in alcohol-dependent individuals while bipolar and depressed subjects may have more episodic pattern of alcohol intake. The latter may lead to shorter periods of intake compared to the chronic and frequent use of this substance in alcohol-dependent individuals and higher biomarkers of alcohol use.